Scientists suggest that ancient volcanoes were responsible for water on Mars

The eruption of Martian volcanoes 3.7 billion years ago could have made the planet warm enough to host liquid water, according to a new study published in the journal Nature Geoscience.

This theory potentially answers a question that has puzzled scientists. Mars’ surface geologically shows evidence of liquid water having once flowed there, yet the planet has always been too cold for water to exist in liquid form rather than freeze into ice.

Mars’ atmosphere is too thin to warm the planet enough for it to harbor liquid water.

In their paper, scientist and co-author James Head, along with colleagues at Brown University and at the Weizmann Institute of Science, focused on the process by which a large-scale series of volcanic eruptions may have released emissions of sulfur, warming up the planet.

While the warming periods produced by these emissions were temporary, they could have lasted decades or centuries, long enough for water ice to melt into liquid water, especially in daytime sunlight.

Head compares this possible ancient Martian scenario with current conditions in some sections of Antarctica, where water ice melts in the warmth of summer temperatures, then cools when those temperatures drop with the approach of winter.

Algal mats, simple life forms in Antarctica, remain dormant during cold periods but actively develop when local ice melts into water. Ancient Martian life might have followed the same pattern, Head believes.

The new findings can help narrow the search for signs of ancient Martian life to old river floors and beds that are now dry and lifeless.

If Mars did once host microbial life, these areas are the most likely places for finding traces of that life, Head emphasizes.

Computer models of Mars’ climate indicate the warming periods it experienced were episodic rather than constant.